How is loss of future earning capacity assessed in a motor vehicle accident case?

He refers to Graham v. Rourke[9] for the position that where loss of future earning capacity is an issue, the value of the loss is to be assessed taking into account the following considerations: whether the plaintiff has been rendered less capable overall from earning income from all types of employment; whether the plaintiff is less marketable or attractive as an employee to potential employers; whether the plaintiff has lost the ability to take advantage of all job opportunities which might otherwise have been open to him, had he not been injured; and whether the plaintiff is less valuable to himself as a person capable of earning income in a competitive labour market.